One River, Many Users

In the picture

1. 1Dam reservoir: stores snowmelt and rain so water can be released when needed
2. 2Irrigation canal: farming usually takes the largest share of the water
3. 3Industrial pipe: factories use water for cooling, cleaning and production
4. 4Town supply pipe: drinking water and household use for the people who live there
5. 5River downstream: what is left after all the withdrawals, sometimes too little for wildlife

Examples

• In a dry summer, a town may ban garden watering so there is enough drinking water
• Farmers switch from flooding fields to drip irrigation so they use less water

Quiz: One River, Many Users (Age 15)

1. 1

   Worldwide, which activity uses the largest share of the freshwater that people withdraw?

   • Agriculture, mostly for irrigating crops
   • Industry, for cooling, cleaning and production
   • Towns, for drinking water and household use
2. 2

   A factory starts taking much more water from a river that it shares with farms and a town. What is the most likely result?

   • Only the factory feels the effect, because each user has its own separate supply
   • Less water is left for the farms, the town and nature downstream
   • The dam reservoir automatically makes up the difference, so nobody else is affected
3. 3

   What does sharing one river fairly between farms, factories and a town usually require?

   • Letting each user take as much as it needs, since a river keeps flowing
   • Managing it with rules, prices or quotas that balance the different needs
   • Building a dam, which ends the need for any choices about sharing

The answers, each with its explanation, are in the app. This quiz is free there while the lesson is in the free week.